iPhone storage full?
Here's what to do first.

Why does iPhone storage fill up?

Photos and videos are usually the biggest part. A minute of 4K video at 30 fps takes about 170 MB in High Efficiency format and about 350 MB in Most Compatible, and bursts, screenshots and near-identical shots add up quietly. Apps, their caches and System Data make up most of the rest.

1. See what's using space

Open Settings › General › iPhone Storage. Wait for the bar to load: it lists every app by size, biggest first, with recommendations at the top.

2. Clear duplicates and screenshots

The Photos app's Duplicates album merges exact copies. It is under Utilities in Photos — on iOS 26 or later, tap Collections first. Near-identical shots, bursts, screenshots and blurry photos need a closer look — that is what Phone Cleaner groups for you, keeping the best shot of each moment.

3. Shrink your biggest videos

Sort videos by size and compress the largest ones. A medium setting makes most videos much smaller with little visible change; keep the originals if you want to compare first.

4. Offload apps you don't use

Turn on Settings › Apps › App Store › Offload Unused Apps. When space runs low, iOS removes apps you rarely open but keeps their documents and data; tap an app's icon to reinstall it.

What is System Data?

System Data is caches, logs and temporary files iOS manages itself. It shrinks on its own over time; restarting your iPhone often reduces it.